A logical partition (“LPAR”) may be created on a computer, such as a mainframe computer in a data center. An LPAR may be considered a virtual machine. Traditionally, an LPAR is created by allocating a processor, memory, dedicated input/output (“I/O”) devices, and at least one Direct Access Storage Device (“DASD,” e.g., a hard disk drive, etc.) that are within or that are physically attached to the computer. The computer includes enough physical resources to support a plurality of LPARs. An LPAR is booted from the DASD, which contains a disk image of an operating system that runs on the LPAR.
An LPAR can be managed over a dedicated management network from a support element connected to the computer hosting the LPAR. The support element can be a second computer, such as a laptop computer, in the data center. Typically, the dedicated management network is separate from a general data network also connected to the computer hosting the LPAR. The general data network is used by an application executing in the LPAR for ordinary networking purposes, while the dedicated management network is utilized only for managing the computer from the support element. The general data network and the dedicated management network will typically have separate hardware network connections on the computer.
Each LPAR on the computer is operated under a special management program called a hypervisor that resides on the “bare” computer. The hypervisor primarily carries out instruction emulation, memory management, I/O processing, and scheduling for each LPAR. Generally, the support element can communicate with the hypervisor via the dedicated management network, but the support element cannot directly communicate with an LPAR's resources (e.g., its processor, memory, I/O devices, or DASD, etc.). As such, the support element typically cannot write a disk image to an LPAR's DASD. From the opposite perspective, an LPAR typically cannot communicate with the support element or anything else reachable via the dedicated management network, and instead can only communicate with the “outside world” via the general data network.
The creation, deployment, and upgrade of disk images used for booting up LPARs is required in various scenarios, such as the provisioning and managing of systems in a cloud computing environment. The deployment of a disk image, and the upgrade of a disk image, can each be regarded as the installation of a disk image. As stated above, the support element from which an administrator executes and controls all administrative actions, cannot typically access an LPAR's DASD. Instead, the only way to install (i.e., to deploy or to upgrade, etc.) a disk image is to manually provide a new DASD that already contains the desired disk image, assign the new DASD to an LPAR, and reboot the LPAR from the new DASD.